1. Field of This Invention
This invention relates to a process for the production of 2-chloronicotinic acid from nicotinic acid-N-oxide.
2. Prior Art
2-CHLORONICOTINIC ACID HAS BEEN PRODUCED FROM NICOTINIC ACID-N-oxide with PCl.sub.5 in the presence of POCl.sub.3. It is also known to react (convert) nicotinic acid-N-oxide with phosphorous oxychloride in the presence of a tertiary organic amine or of a carboxylic acid amide (East German Pat. No. 80,209). However, in the case of such known process, colored end products result which cannot be decolored, even with repeated recrystallization. Purifying processes using activated charcoal, despite the use of high portions of activated charcoal related to the product to be purified, do not achieve the desired goal. According to East German Pat. No. 80,209, additions of alkalines (1yes) is necessary, but, which with regard to purity of the product, has no advantageous effect and leads to increased loading of the effluent.